Flex报错一

错误： 

 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf - 解压缩后为 170,406 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\1 - 解压缩后为 2,292,131 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\2 - 解压缩后为 648,239 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\3 - 解压缩后为 370,463 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\4 - 解压缩后为 441,686 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\5 - 解压缩后为 1,429,050 个字节
 [SWF] D:\Adobe Flash Builder 4 Installer\workspace\bin-debug\IfElse.swf\[[DYNAMIC]]\6 - 解压缩后为 323,414 个字节
TypeError: Error #1034: 强制转换类型失败:无法将 "请输入密码！" 转换为 mx.controls.Alert。
at com.you.test::IfElse/checkPassword()[D:\Adobe Flash Builder 4 Installer\workspace\src\com\you\test\IfElse.mxml:20]
at com.you.test::IfElse/___IfElse_Button1_click()[D:\Adobe Flash Builder 4 Installer\workspace\src\com\you\test\IfElse.mxml:42]

错误原因：Alert打印出字符串或其它对象，Alert("密码");

解决办法：将之前的Alert(" ");改为Alert.show(" ");